ML18033B559
| ML18033B559 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 11/20/1990 |
| From: | Varga S Office of Nuclear Reactor Regulation |
| To: | Kingsley O TENNESSEE VALLEY AUTHORITY |
| Shared Package | |
| ML18033B560 | List: |
| References | |
| NUDOCS 9011300112 | |
| Download: ML18033B559 (9) | |
Text
pe REGS~
ci C1/+
~p p
p Op V/~
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 November 20, 1990 Docket Nos. 50-259, 50-260 and 50-296 Hr. Oliver D. Kingsley, Jr.
Senior Vice President, Nuclear Power Tennessee Valley Authority 6N 38A Lookout Place 1101 Market Street Chattanooga, Tennessee 37402-2801
Dear Hr. Kingsley:
SUBJECT:
TVA BACKFIT CLAIM REGARDING THE NRC'S SAFETY EVALUATION CF THE POTENTIAL IMPACT OF HAZARDOUS CHEMICALS TRANSPORTED BY BARGES UPON HABITABILITYOF THE CONTROL ROOM AT BROIlINS FERRY I
L By letter dated December 19, 1989, the NPC staff requested the Tennessee Valley Authority (TVA) (the licensee) to perform an evaluation of the probable effects from an accidental release of toxic chemical(s) transported by barges on the Tennessee River upon control room habitability at the Browns Ferry Nuclear (BFN)
Plant.
This request was based on the guidance provided in Regulatory Guide (RG) 1.78, "Assumptions For Evaluating The Habitability Cf A Nuclear Power Plant Control Room During A Postulated Hazardous Chemical Release",
which states that such an evaluation is warranted whenever the shipment frequency of all toxic chemicals transported by barges is equal to or greater than 50 shipments per year (more than a'undred barges carrying hazardous chemicals pass by BFN each year).
By letter dated May 31, 1990, TVA responded to the staff 's request with its evaluation even though TVA indicated that, according to its interpretation of RG 1.78, this evaluation was not necessary because the criterion of 50 shipments per year does not apply to an aggregate of toxic chemicals transported by barges, but only to each individual chemical.
The staff reviewed TVA's evaluation and by letter datete September 14, 1990, issued a Safety Evaluation Report (SER).
This SER determined that TVA's evaluation was acceptable with the following caveat - TVA institutes the appropriate compensatory measures (i.e.
emergency procedures and training) outlined in RG 1.78 for five of the hazardous chemicals
( i.e. those identified by TVA as slow in building up to toxic concentrations),
or TVA conducts additional analysis to support a determination that these measures are unwarranted because the probablistic risk is sufficiently low.
Prior to issuing this SER, the staff specifically took under consideration the prospects of whether this caveat constituted a potential backfit.
At that time, the staff concluded it was not a backfit.
1 In a letter dated October 15, 1990, TVA took exceptionI to the staff's caveat, and requested that the present NRC position (i.e. threshold limit of RG 1.78 is for a total of fifty barges per year of all chemicals combined) be reconsidered under the standards of 10 CFR 50.109, "BacEfitting."
TVA justified its backfit claim by referencing previous NRC licensing actions and regulatory guidance.
According to TVA, the NRC's past interpretation of RG 1.78 regarding the threshold limit for shipment frequency of toxic chemicals has been inconsistent.
One of the examoles cited by TVA was NUREG/CR-5042, "Evaluation 9011300112 901120 PDR ADOCK 05000259 tlj P
I
Nr. Oliver D. Kingsley, Jr.
of External Hazards to Nuclear Plarits in the United States
- December 1987".
In this NUREG a statement was made implying that the shipment frequercy of each ir;dividual chemical should be used in determiring if this chemical should be considered in evaluatiiig habitability of the coritrol room.
Although the NUREG clearly interprets RG 1.78 incorrectly, it does support TVA's coritention.
Another example cited by TVA was ar, NRC letter dated October 21, 1988 in which the staff agreed with TVA's finding that chloririe need not be considered because its shiprrerit frequency is below the limits of RG 1.78.
However, this SER was only applicable to TVA's evaluaticn as presented in the letter dated tray 26, 1987 in which the only toxic cheii:ical considered was chlorine.
Even though there is no clear evidence to suggest that the NRC explicitly approved TVA's positiori regarding the shipment frequency of individual chemicals, iri reflection, the staff position ori this issue (as stated in tie SER) was ambiguous and could be misconstrued as tacit approval of the TVA positiori.
According to internal NRC procedures, a
new staff position may be a backfit if it would require the licensee to change plant operation frcrii that which is already corisistent with applicable regulatory staff positions.
Furthermore, an applicable regulatory staff position (e.g.
RG 1.78) will not be considered applicable with respect to a particular licensee if the staff, in previous licensing actions, tacitly excepted the licersee frorri part or all of the staff's position.
Applying these criteria to the Brcwns Ferry case, TVA's claim is justified, at least partially, because:
(a)
NUREG/CR-5042 made ari erroreous interpretatiori of the RG 1.78 guidance, which appears to be consistent with TVA's
- position, and (b) the staff's SER of October 21, 1988 approved of TVA's evaluation without explicitly statirig that the determination for shipmerit frequency must inc luce a 1 1 tox ic chemi ca 1 s.
However, since the basis of TVA's backfit claim is justified solely on the grounds of inadvertant technicalities (i.e.,
ari erronecus interpretation of RG 1.78 and an ambigous staff SER), the staff assessed the safety implications of not requiririg TVA to implement compensatory measures.
Details of, the staff's safety evaluation are enclosed.
This supplemental SER addressed the probabilistic frequercy of a toxic gas release invadirig the control room, using the assumption that all toxic chemicals transported by barges are considered.
In this SER, the staff concludes that the chances of exceeding 10 CFR Part 100 guidelines as a
consequence of a toxic gas release frcm damaged
- barges, are very small (well below 1E-6 per year) and according to Standard Review Plan (SRP), Section 2.2.3 need not be considered.
- Thus, based upon the additional information contained in TVA's letter of October 15, 1990, and the staff' better under standing of TVA' position, the staff concludes that although TVA's interpretation cf RG 1.78 is incorrect, its backfit claim is justified for the aforeireriticned reasons.
Additionally, the staff has determined that impositiori of this backfit is rct necessary to bririg the plant into compliance with regulatory requirements or to ensure adequate public health arid safety.
Since the staff does not envision that any regulatory aralysis would justify the costs of further implementation by TVA due to the lack of a substantial increase in safety or overall protection, the NRC is withdrawing its previous. caveat.
Nr. Oliver D. Kingsley, Jr. Consequently, the open issues regarding additional compensatory nieasures or aralysis recuested by the staff in its SER of September 14, 1990, are considered resolved.
S incere ly,
Enclosure:
As stated n
rga, Dire r
Division of Reactor P
cts - I/II Office of Nuclear Reactor Regulation cc:
See next page
Mr. Oliver D. Kingsley, Jr.
Consequently, the open issues regarding additional compensatory measures or analysis requested by the staff in its SER of September 14, 1990, are considered resolved.
Sincerely, OHgfna1 soigne'd by:
Enclosure:
As stated cc:
See next page Steven A. Varga, Director Division of Reactor Projects - I/II Office of huclear Reactor Regulation RZ=:VDTI=47U=:7M>:4/N:%M NAME
- MKrebs~g
- TRoss ~>
g:SB dd DATE
- 11/i5 /90
- 11/l5 /90
- 11/
UFFIRIRI. RRRRRR RRR Document flame:
/90
- 11/ ~ L./90
- 07M:VDI 0/D
~ & ~
- FHeb on 5Ãp:Ao A
~
WWO 0 4 ~
\\ &
GL.ir s:SV 11/ //R/90
- 11 90
1, A
Pr. 0'liver D. Kingsley, Jr. CC:
t4r. Harvin Runycn, Chairman Ternessee Valley Authority ET 12A 7A 400 West Summit Hill Drive Knoxville, Tennessee 37902 Hr. Edward G. Wallace
- tlanager, tluclear Licensir:g and Regulatory Affairs Tennessee Valley Authority 5H 157B Lookout P la ce Chatt<<riooga, Tennessee 37402-2801 Hr. John B. Waters, Director Tennessee Valley Authority ET 12A 9A 400 West Sumrrit Ilill Drive Knoxville, Tennessee 37902 Hr.
W. F. Willis Chief Operating Officer ET 12B 16B 400 West Summit Hill Drive Knoxville, Tennessee 37902 General Counsel Tennessee Valley Authority 400 West Summit Hill Drive ET 11B 33H Knoxville, Tennessee 37902 Vr. Dwight Hunn Vice Pres ider;t, tlu c 1 ear Pro sects Ter.nessee Valley Authority 6tl 38A Lookout Place 1101 Harket Street Chattanooga, Tennessee 37402-2801 Dt. Hark 0. Nedford Vice Presider!t, tiuclear Assurance, Licensing and Fuels Tennessee Valley Autho! ity 6t< 38A Lookout Place Chattanooga, Tennessee 37402-2801 Nr. 0. J. 7eringue, Site Director Drowns Ferry Yuclear Plant Tennessee Valley Authority P. 0.
Box 2CCC
- Decatur, Alabama 35602 Hr. P. Carier, Site Licensirig tlanager Browns Ferry tluclear Plant Ter,nessee Valley Authority P. 0.
Box 2000
- Decatur, Alabama 35602 tlr. L.
W, Hyers, Plant Yanager Browns Ferry nuclear Plant Tennessee Valley Authority P. 0.
Box 2000
- Decatur, A'labama 35602 Chairrrar., Lim<<store County Commission P. 0.
Box 188
- Athens, A 1abama 35611 Claude Earl Fox, H.D.
State Health Officer State Department of Public Health State Office Building tlor!tgcmery, Alabama 36130 Regior!al Administr ator, Region II U.S. t',uclear Regulatory Commission 101 marietta Street, N.W.
Atlanta, Georgia 30323 Hr. Charles Patterson Senior Resident Inspector Browns Ferry tluclear Plart U.S. Yuclear Regulatory Co!rmission Route 12, Box 637
- Athens, Alabama 35611 Tenressee Valley Authority Rockvi lie Office 11921 Rockville Pike Rockvi lie, Yaryland 20852